However, several of the versions listed in your error messages are marked as internal releases or otherwise not available.

I don't think these messages are anything to worry about. As you can see, firmware was eventually loaded (-22). My understanding of the driver is that it tries to load the newest version it knows about, and continues looking for earlier versions until it finds one.

I don't see -26 mentioned there at all, and -25, -24, and -23 are all marked internal release.

and none of the missing releases versions are in there--it jumps from the -22 to the -27 version. Internal releases mean that those versions are not available to the public. I am guessing the driver in the 4.10 kernel would also ask about a missing -27 version, unless Debian has it in an updated package down the line. From what I've seen in other forums, the message is just information for the user as horgh says, not a fatal type of error, so that's why there is no urgency in getting rid of it.